1. Field
This disclosure relates to a micro manipulator for an electrode movement, and more particularly, to a micro manipulator capable of improving positioning resolution and positioning ability of an electrode disposed adjacent to a subject's neuron or an electrode holder attached with the electrode with a simple structure.
2. Description of the Related Art
A living organism has numerous neurons, and the neurons are used as information transmitting means. A method of transmitting information between neurons is understood as an electrical signal transmitting and receiving process. That is, the neurons transmit information to other neurons via an electrical signal. This means that the neurons are sensitive to the external electrical stimulus.
Electrophysiology is the study of relationships between the living organism and the electricity. In other words, electrophysiology is the study examining an influence of the electricity on the living body and an electrical phenomenon occurring in the living body. Electrophysiology has been rapidly developed with the development of electronic engineering and the technology of inserting an electrode into a cell.
It is known that there exist about 1011 neurons in the human brain. The neurons in the brain determine the function of the brain, and are classified variously according to their functions. Accordingly, in order to understand the function of the brain, it is necessary to analyze the role and the operation of the brain neurons. For the purpose of analyzing the function of the brain neurons, there is proposed a method of analyzing the electric characteristic of the brain neurons in accordance with the external stimulus and the reaction of the living body in accordance with the electrical stimulus for specific brain neurons. However, since the electrical stimulation method cannot be performed on the human, experiments are carried out on animals.
FIG. 1 is a schematic conceptual diagram showing an experiment device which is used for an experiment for examining a relationship between the brain neuron and electricity. As shown in FIG. 1, generally, a small animal such as a mouse is used as a subject for the experiment for examining the relationship between the brain neuron and electricity. In order to locate an electrode, which detects an electrical signal of the subject's brain neuron and applies an electrical signal to the brain neuron, so as to be adjacent to the brain neuron, a micro manipulator 1 is used. The micro manipulator 1 is connected to an external signal processing device 2. The external signal processing device 2 includes a controller which controls an operation of the micro manipulator 1, a signal processing portion which converts an electrical signal generated from the electrode into a digital signal and analyzes the result, or the like.
Since the brain is the most sensitive organ, a process of applying the electrical stimulus to the brain neuron or extracting the electrical signal therefrom has to be performed very carefully. Accordingly, in the above-described brain neuron electrical signal analyzing device, the micro manipulator for performing an operation of moving the electrode to be adjacent to the brain neuron plays a very important role from the viewpoint of obtaining accurate experimental data and of protecting the living body.
In the past, in order to perform the operation of moving the electrode to be adjacent to the brain neuron, a manual micro manipulator or a micro manipulator using a small motor was used.
In the manual micro manipulator, an operator needs to restrain the animal used in the experiment and to operate a moving device. Accordingly, the experiment is difficult, and the positioning ability of the electrode deteriorates due to the manual operation. In addition, a problem arises in that the electrode may be detached from the neuron to be recorded due to the subject animal's resistance.
In order to solve the above-described problems, a micro manipulator using an existing small motor is developed. However, since the known micro manipulator includes a gear portion transmitting an operation of the motor, a moving device such as a screw used for the linear movement of the electrode, and the like, a problem arises in that a longitudinal length of the manipulator increases and a structure is complex. In addition, since an error occurs easily in a meshing operation between various mechanical components such as reduction gears and a screw, a problem arises in that the resolution of the micro manipulator for moving the electrode is not high and the control ability deteriorates due to the low resolution.